Aims

The aim of this study was to estimate the incremental use of resources, costs, and quality of life outcomes associated with surgical reconstruction compared to rehabilitation for long-standing anterior cruciate ligament (ACL) injury in the NHS, and to estimate its cost-effectiveness.

Aims

To map the Oxford Knee Score (OKS) and High Activity Arthroplasty Score (HAAS) items to a common scale, and to investigate the psychometric properties of this new scale for the measurement of knee health.

Aims

Routinely collected patient-reported outcome measures (PROMs) have been useful to quantify and quality-assess provision of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in the UK for the past decade. This study aimed to explore whether the outcome following primary THA and TKA had improved over the past seven years.

Aims

To estimate the measurement properties for the Oxford Knee Score (OKS) in patients undergoing revision knee arthroplasty (responsiveness, minimal detectable change (MDC-90), minimal important change (MIC), minimal important difference (MID), internal consistency, construct validity, and interpretability).

Aims

To calculate how the likelihood of obtaining measurable benefit from hip or knee arthroplasty varies with preoperative patient-reported scores.

Aims

The aim of this study was to determine the long-term risk of undergoing knee arthroplasty in a cohort of patients with meniscal tears who had undergone arthroscopic partial meniscectomy (APM).

Aims

The aim of the British Association for Surgery of the Knee (BASK) Meniscal Consensus Project was to develop an evidence-based treatment guideline for patients with meniscal lesions of the knee.

Aims

The aims of this study were to compare the use of resources, costs, and quality of life outcomes associated with subacromial decompression, arthroscopy only (placebo surgery), and no treatment for subacromial pain in the United Kingdom National Health Service (NHS), and to estimate their cost-effectiveness.

Aims

The appropriate management for patients with a degenerative tear of the rotator cuff remains controversial, but operative treatment, particularly arthroscopic surgery, is increasingly being used. Our aim in this paper was to compare the effectiveness of arthroscopic with open repair of the rotator cuff.

Aims

The aim of this to study was to compare the previously unreported long-term survival outcome of the Oxford medial unicompartmental knee arthroplasty (UKA) performed by trainee surgeons and consultants.

We assessed the orientation of the acetabular component in 1070 primary total hip arthroplasties with hard-on-soft, small diameter bearings, aiming to determine the size and site of the target zone that optimises outcome. Outcome measures included complications, dislocations, revisions and ΔOHS (the difference between the Oxford Hip Scores pre-operatively and five years post-operatively). A wide scatter of orientation was observed (2sd 15°). Placing the component within Lewinnek’s zone was not associated withimproved outcome. Of the different zone sizes tested (± 5°, ± 10° and ± 15°), only ± 15° was associated with a decreased rate of dislocation. The dislocation rate with acetabular components inside an inclination/anteversion zone of 40°/15° ± 15° was four times lower than those outside. The only zone size associated with statistically significant and clinically important improvement in OHS was ± 5°. The best outcomes (ΔOHS > 26) were achieved with a 45°/25° ± 5° zone.

This study demonstrated that with traditional technology surgeons can only reliably achieve a target zone of ±15°. As the optimal zone to diminish the risk of dislocation is also ±15°, surgeons should be able to achieve this. This is the first study to demonstrate that optimal orientation of the acetabular component improves the functional outcome. However, the target zone is small (± 5°) and cannot, with current technology, be consistently achieved.

Cite this article: Bone Joint J 2015;97-B:164–72.

Objective

The objective of this study was to explore dimensionality of the Oxford Hip Score (OHS) and examine whether self-reported pain and functioning can be distinguished in the form of subscales.

Aims

Femoroacetabular Junction Impingement (FAI) describes abnormalities in the shape of the femoral head–neck junction, or abnormalities in the orientation of the acetabulum. In the short term, FAI can give rise to pain and disability, and in the long-term it significantly increases the risk of developing osteoarthritis. The Femoroacetabular Impingement Trial (FAIT) aims to determine whether operative or non-operative intervention is more effective at improving symptoms and preventing the development and progression of osteoarthritis.

This protocol describes a pragmatic multicentre randomised controlled trial (RCT) to assess the clinical and cost effectiveness of arthroscopic and open surgery in the management of rotator cuff tears. This trial began in 2007 and was modified in 2010, with the removal of a non-operative arm due to high rates of early crossover to surgery.

Cite this article: Bone Joint Res 2014;3:155–60.

The primary aim of this study was to develop a patient-reported Activity & Participation Questionnaire (the OKS-APQ) to supplement the Oxford knee score, in order to assess higher levels of activity and participation. The generation of items for the questionnaire involved interviews with 26 patients. Psychometric analysis (exploratory and confirmatory factor analysis and Rasch analysis) guided the reduction of items and the generation of a scale within a prospective study of 122 relatively young patients (mean age 61.5 years (42 to 71)) prior to knee replacement. A total of 99, completed pre-operative and six month post-operative assessments (new items, OKS, Short-Form 36 and American Knee Society Score).

The eight-item OKS-APQ scale is unidimensional, reliable (Cronbach’s alpha 0.85; intraclass correlation coefficient (ICC) 0.79; or 0.92 when one outlier was excluded), valid (r >  0.5 with related scales) and responsive (effect size 4.16).

We recommend that it is used with the OKS with adults of all ages when further detail regarding the levels of activity and participation of a patient is required.

Cite this article: Bone Joint J 2014;96-B:332–8.

We conducted a randomised controlled trial to determine whether active intense pulsed light (IPL) is an effective treatment for patients with chronic mid-body Achilles tendinopathy. A total of 47 patients were randomly assigned to three weekly therapeutic or placebo IPL treatments. The primary outcome measure was the Victorian Institute of Sport Assessment – Achilles (VISA-A) score. Secondary outcomes were a visual analogue scale for pain (VAS) and the Lower Extremity Functional Scale (LEFS). Outcomes were recorded at baseline, six weeks and 12 weeks following treatment. Ultrasound assessment of the thickness of the tendon and neovascularisation were also recorded before and after treatment.

There was no significant difference between the groups for any of the outcome scores or ultrasound measurements by 12 weeks, showing no measurable benefit from treatment with IPL in patients with Achilles tendinopathy.

Cite this article: Bone Joint J 2013;95-B:504–9.

Introduction

A prospective study was done using Kirschner (K) wires to internally fix capitellum fractures and its results were analysed.

Objectives

The number of surgical procedures performed each year to treat femoroacetabular impingement (FAI) continues to rise. Although there is evidence that surgery can improve symptoms in the short-term, there is no evidence that it slows the development of osteoarthritis (OA). We performed a feasibility study to determine whether patient and surgeon opinion was permissive for a Randomised Controlled Trial (RCT) comparing operative with non-operative treatment for FAI.

We present a comparison of patient-reported outcomes (PROMs) in relation to patient age, in patients who had received a total (TKR) or unicompartmental knee replacement (UKR). The outcome was evaluated using the Oxford knee score (OKS), EuroQol (EQ-5D) and satisfaction scores. Patients aged 65 to 84 years demonstrated better pre-operative function scores than those aged < 65 years (OKS, p = 0.03; EQ-5D, p = 0.048) and those aged ≥ 85 years (OKS, p = 0.03). Post-operative scores were comparable across age groups, but a linear trend for greater post-operative improvement in OKS and EQ-5D was seen with decreasing age (p < 0.033). The overall mean satisfaction score at six months was 84.9, but those aged <  55 years exhibited a lower mean level of satisfaction (78.3) compared with all other age groups (all p < 0.031). The cumulative overall two-year revision rate was 1.3%. This study demonstrates that good early outcomes, as measured by the OKS and EQ-5D, can be anticipated following knee replacement regardless of the patient’s age, although younger patients gain greater improvement. However, the lower satisfaction in those aged < 55 years is a concern, and suggests that outcome is not fully encapsulated by the OKS and EQ-5D evaluation, and raises the question whether the OKS alone is an appropriate measure of pain and function in younger, more active individuals.

Cite this article: Bone Joint J 2013;95-B:38–44.

Rheumatology and Musculoskeletal Sciences, NIHR Biomedical Research Unit, University of Oxford and the Nuffield Orthopaedic Hospital, Oxford

Femoral stem varus has been associated with poorer results. We report the incidence of varus/valgus malalignment of the Exeter polished, double taper design in a multicentre prospective study. The surgical outcomes at a minimum of five year and complication rates are also reported.

A multicentre prospective study of 987 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and femoral stem malalignment. The primary outcome measure was the change in the Oxford hip score (OHS) at five years. Secondary outcomes included the rate of dislocation and revision.

The incidence of varus and valgus malignment were 7.1% and 2.6% respectively. There was no significant difference in OHS between neutral and malaligned femoral stems at 5 years (neutral, mean = 40.2; varus, mean 39.3, p = 0.465; valgus, mean = 40.9, p = 0.605). There was no significant difference in dislocation rate between the groups (p = 0.66). There was also no significant difference in revision rate (p = 0.34).

This study provides evidence that the Exeter stem is extremely tolerant of varus and valgus malalignment, both in terms of outcome and complication rate.

Patella subluxation assessed on dynamic MRI has previously been shown to be associated with anterior knee pain. In this MRI study of 60 patients we investigated the relationship between subluxation and multiple bony, cartilaginous and soft-tissue factors that might predispose to subluxation using discriminant function analysis.

Patella engagement (% of patella cartilage overlapping with trochlea cartilage) had the strongest relationship with subluxation. Patellae with > 30% engagement tended not to sublux; those with < 30% tended to sublux. Other factors that were associated with subluxation included the tibial tubercle-trochlea notch distance, vastus medialis obliquus distance from patella, patella alta, and the bony and cartilaginous sulcus angles in the superior part of the trochlea. No relationship was found between subluxation and sulcus angles for cartilage and bone in the middle and lower part of the trochlea, cartilage thicknesses and Wiberg classification of the patella.

This study indicates that patella engagement is a key factor associated with patellar subluxation. This suggests that in patients with anterior knee pain with subluxation, resistant to conservative management, surgery directed towards improving patella engagement should be considered. A clinical trial is necessary to test this hypothesis.

We have compared the outcome of hemiarthroplasty of the shoulder in three distinct diagnostic groups, using survival analysis as used by the United Kingdom national joint registers, patient-reported outcome measures (PROMs) as recommended by Darzi in the 2008 NHS review, and transition and satisfaction questions.

A total of 72 hemiarthroplasties, 19 for primary osteoarthritis (OA) with an intact rotator cuff, 22 for OA with a torn rotator cuff, and 31 for rheumatoid arthritis (RA), were followed up for between three and eight years. All the patients survived, with no revisions or dislocations and no significant radiological evidence of loosening. The mean new Oxford shoulder score (minimum/worst 0, maximum/best 48) improved significantly for all groups (p < 0.001), in the OA group with an intact rotator cuff from 21.4 to 38.8 (effect size 2.9), in the OA group with a torn rotator cuff from 13.3 to 27.2 (effect size 2.1) and in the RA group from 13.7 to 28.0 (effect size 3.1). By this assessment, and for the survival analysis, there was no significant difference between the groups. However, when ratings using the patient satisfaction questions were analysed, eight (29.6%) of the RA group were ‘disappointed’, compared with one (9.1%) of the OA group with cuff intact and one (7.7%) of the OA group with cuff torn. All patients in the OA group with cuff torn indicated that they would undergo the operation again, compared to ten (90.9%) in the OA group with cuff intact and 20 (76.9%) in the RA group.

The use of revision rates alone does not fully represent outcome after hemiarthroplasty of the shoulder. Data from PROMs provides more information about change in pain and the ability to undertake activities and perform tasks. The additional use of satisfaction ratings shows that both the rates of revision surgery and PROMs need careful interpretation in the context of patient expectations.

Introduction: Patellofemoral joint subluxation is associated with pain and dysfunction. The causes of patel-lofemoral subluxation are poorly understood and multi-factorial, arising from abnormalities of both bone and soft tissues. This study aims to identify which anatomical variables assessed on Magnetic Resonance (MR) images are most relevant to patellofemoral subluxation.

Method: A retrospective analysis of MR studies of 60 patients with suspected patellofemoral subluxation was performed. All patients were graded for the severity/ magnitude of radiological subluxation using a dynamic MR scan (Grade 0 [nil] to Grade 3 [subluxed]. The patient scans were assessed using a range of anatomical variables, these included:

Patella alta,

Results: The distance of the VMO from the patella (p < 0.001), TTD (p < 0.001) and Patella Engagement (p < 0.001) showed highly significant relationships with patellofemoral subluxation.

Conclusions: The following three anatomical variables are associated with patellofemoral subluxation: the distance of the VMO muscle from the patella, TTD and Patella Engagement.

This is the first study to establish that patella engagement is related to PFJ subluxation showing that the lower the percentage engagement of the patella in the trochlea, the greater the severity/magnitude of patellofemoral subluxation. The finding provides greater insight into the aetiology and understanding of the mechanism of symptomatic PFJ subluxation.

Using the General Practice Research Database, we examined the temporal changes in the rates of primary total hip (THR) and total knee (TKR) replacement, the age at operation and the female-to-male ratio between 1991 and 2006 in the United Kingdom.

We identified 27 113 patients with THR and 23 843 with TKR. The rate of performance of THR and TKR had increased significantly (p < 0.0001 for both) during the 16-year period and was greater for TKR, especially in the last five years. The mean age at operation was greater for women than for men and had remained stable throughout the period of study. The female-to-male ratio was higher for THR and TKR and had remained stable.

The data support the notion that the rate of joint replacement is increasing in the United Kingdom with the rate of TKR rising at the highest rate. The perception that the mean age for TKR has decreased over time is not supported.

Purpose: Varus deformity after total knee replacement (TKR) is associated with poor outcome. This aim of this study was to determine whether the same is true for medial unicompartmental arthroplasty (UKA).

Methods: 158 patients implanted with the Oxford UKA, using a minimally invasive approach, were studied prospectively for five years. Leg alignment was measured with a long-arm goniometer referenced from Anterior Superior Iliac Spine, centre of patella and centre of ankle. Patients were grouped according to the American Knee Society Score (AKSS). Group A: > 0° varus (n=13, 8.2%); Group B: 0 to 4° valgus (n=39, 24.7%); Group C: 5–10° valgus (normal alignment, n=106, 67.12%). Comparisons were made between the three groups in terms of the absolute and the change in Oxford Knee Score (OKS) and AKSS over the five year period, and the presence of radiolucency.

Results: There was no significant difference in any outcome measure except for Objective-AKSS (p< 0.001). The means and standard deviations of the ΔOKS for the groups were:

24 ± 5,

The frequency of five year radiolucency for the groups A, B, and C were 42%, 35%, and 45% respectively.

Conclusion: The aim of the Oxford UKA is to restore knee kinematics and thus knee alignment to the pre-disease state. Therefore, as demonstrated by this study, about 30% of patients have varus alignment. This study also demonstrates that post-operative varus alignment does not compromise the outcome. The only score which did show worse outcome was the Objective-AKSS. This is because 10 or 20 points are deducted for varus alignment, which is not appropriate following UKA. Therefore, AKSS in its present form is not a reliable tool for assessment of UKA.

Purpose: To evaluate the effects of underhanging/overhanging tibial components on clinical outcome following the Oxford unicompartmental knee arthroplasty (UKA), and to identify an acceptable sizing limit.

Method: One hundred and sixty-three knees which had undergone the Phase 3 medial Oxford UKA (Biomet, Swindon) were measured. Based on five-year post-operative radiographs, they were divided into groups with tibial component underhang (n=38), none or minimal overhang of less than three millimetres (n=121), and a group with overhang equal to or in excess of three millimetres (n=13). Clinical outcome was assessed by changes in the twelve-question Oxford Knee Score (ΔOKS) and pain score (ΔPS) component (questions 1,4,5,8,9) from pre-operative assessment to five years following surgery.

Results: At five years after surgery, ΔOKS was significantly worse in the overhang group compared to both the neutral and underhang groups (p=0.015, and p=0.028 respectively). ΔPS was also shown to be significantly worse between the overhang and the neutral group (p=0.026 respectively).

Conclusion: Appropriate sizing of the tibial component is essential to optimise load bearing in total knee arthroplasty. In UKA such sizing is critical due to halving of the bony support for the tibial component and the lack of room for a large stem. Excessive undersizing of the prosthesis may lead to subsidence and loosening, whilst excessive overhanging may cause local soft tissue irritation and pain.

This study demonstrates that medial overhang of less than three millimetres for the tibial component is acceptable in the Oxford UKA. Excessive overhang equal to this or more results in significantly worse ΔOKS and ΔPS. However, no difference in the five year ΔOKS and ΔPS was demonstrated between underhang and the other two groups in this study.

Purpose: To identify associative factors for radiolucency (RL) under the tibial component following the Oxford unicompartmental arthroplasty (UKA), and to evaluate its effect on clinical outcome scores.

Method: One hundred and sixty-one knees which had undergone primary Phase 3 medial Oxford UKA were included. Fluoroscopic radiography films were assessed at five years post-operatively for areas of tibial RL. The two groups of patients, with and without RL, were compared to

patients’ pre-operative demographics for age, weight, height, BMI,

Results: 101 (62%) knees were found to have tibial RL. All RL were categorised as physiological or they were < 1mm thick, with sclerotic margins and non-progressive. No statistical difference was found between knees with RL and those without, in terms of pre-operative demographics, intra- or post-operative factors, and clinical outcome scores (p> 0.1 in all variables).

Discussion: Radiolucency (RL) under the tibial component is a common finding following the Oxford UKA. Many theories have been proposed to explain the cause of RL, such as poor cementing, osteonecrosis, micromotion, and thermal necrosis. However, the true aetiology and clinical significance remain unclear. We attempted to address this.

We found no significant relationship between physiological RL, pre-operative demographics, intra-operative variables and clinical outcome scores in this study. Tibial RL remains a common finding following the Oxford UKA yet we do not know why it occurs but in the medium term, clinical outcome is not influenced by RL. In particular, it is not a sign of loosening. Physiological RL can therefore be ignored even if associated with adverse symptoms following the Oxford UKA.

Inflammatory pseudotumours occasionally occur after metal-on-metal hip resurfacing and often lead to revision. Our aim was to determine the severity of this complication by assessing the outcome of revision in these circumstances and by comparing this with the outcome of other metal-on-metal hip resurfacing revisions as well as that of matched primary total hip replacements.

We identified 53 hips which had undergone metal-on-metal hip resurfacing and required revision at a mean of 1.59 years (0.01 to 6.69) after operation. Of these, 16 were revised for pseudotumours, 21 for fracture and 16 for other reasons. These were matched by age, gender and diagnosis with 103 patients undergoing primary total hip replacement with the Exeter implant.

At a mean follow-up of three years (0.8 to 7.2) the outcome of metal-on-metal hip resurfacing revision for pseudotumour was poor with a mean Oxford hip score of 20.9 (sd 9.3) and was significantly worse (p < 0.001) than the outcome for fracture with a mean Oxford hip score of 40.2 (sd 9.2) or that for other causes with a mean Oxford hip score of 37.8 (sd 9.4). The clinical outcome of revision for pseudotumour was also significantly worse (p < 0.001) than the outcome of matched primary total hip replacements. By contrast, the outcome for fracture and other causes was not significantly different from that of matched primary total hip replacements (p = 0.065). After revision for pseudotumour there were three cases of recurrent dislocation, three of palsy of the femoral nerve, one of stenosis of the femoral artery and two of loosening of the component. Five hips required further revision. In three of these there was evidence of recurrent pseudotumour, and one is currently awaiting further revision. The incidence of major complications after revision for pseudotumour (50%) was significantly higher (p = 0.018) than that after revision for other causes (14%).

The outcome of revision for pseudotumour is poor and consideration should be given to early revision to limit the extent of the soft-tissue destruction. The outcome of resurfacing revision for other causes is good.

Balancing service provision and surgical training is a challenging issue that affects all healthcare systems. A multicentre prospective study of 1501 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and the grade of the operating surgeon, and whether there is any difference in outcome if surgeons’ assistants assist with the operation, rather than orthopaedic trainees. The primary outcome measure was the change in the Oxford hip score (OHS) at five years. Secondary outcomes included the rate of revision and dislocation, operating time, and length of hospital stay.

There was no significant difference in ΔOHS or complication rates between operations undertaken by trainers and trainees, or those at which surgeons’ assistants and trainees were the assistant. However, there was a significant difference in the duration of surgery, with a mean reduction of 28 minutes in those in which a surgeons’ assistant was the assistant.

This study provides evidence that total hip replacements can be performed safely and effectively by appropriately trained surgeons in training, and that there are potential benefits of using surgeons’ assistants in orthopaedic surgery.

We randomised 62 knees to receive either cemented or cementless versions of the Oxford unicompartmental knee replacement. The implants used in both arms of the study were similar, except that the cementless components were coated with porous titanium and hydroxyapatite. The tibial interfaces were studied with fluoroscopically-aligned radiographs.

At one year there was no difference in clinical outcome between the two groups. Narrow radiolucent lines were seen at the bone-implant interfaces in 75% of cemented tibial components. These were partial in 43%, and complete in 32%. In the cementless implants, partial radiolucencies were seen in 7% and complete radiolucencies in none. These differences are statistically significant (p < 0.0001) and imply satisfactory bone ingrowth into the cementless implants.

A prospective, multi-centre study was carried out on 1421 total hip replacements between January 1999 and July 2007 to examine if obesity has an effect on clinical outcomes.

The patients were categorised into three groups: non-obese (body mass index (BMI) < 30 kg/m²), obese (BMI 30 to 40 kg/m²) and morbidly obese (BMI > 40 kg/m²). The primary outcome measure was the change in Oxford hip score at five years. Secondary outcome measures included dislocation and revision rates, increased haemorrhage, deep infection, deep-vein thrombosis and pulmonary embolism, mean operating time and length of hospital stay. Radiological analysis assessing heterotopic ossification, femoral osteolysis and femoral stem positioning was performed. Data were incomplete for 362 hips (25.5%)

There was no difference in the change in the Oxford hip score, complication rates or radiological changes at five years between the groups. The morbidly obese group was significantly younger and required a significantly longer operating time. Obese and morbidly obese patients have as much to gain from total hip replacement as non-obese patients.

Few independent studies have reported the outcome of resurfacing arthroplasty of the hip. The aim of this study was to report the five-year clinical outcome and seven-year survival of an independent series.

A total of 610 Birmingham Hip Resurfacing arthroplasties were performed in 532 patients with a mean age of 51.8 years (16.5 to 81.6). They were followed for between two and eight years; 107 patients (120 hips) had been followed up for more than five years. Two patients were lost to follow-up. At a minimum of five years’ follow-up, 79 of 85 hips (93%) had an excellent or good outcome according to the Harris hip score. The mean Oxford hip score was 16.1 points (sd 7.7) and the mean University of California Los Angeles activity score was 6.6 points (sd 1.9). There were no patients with definite radiological evidence of loosening or of narrowing of the femoral neck exceeding 10% of its width. There were 23 revisions (3.8%), giving an overall survival of 95% (95% confidence interval 85.3 to 99.2) at seven years. Fractured neck of femur in 12 hips was the most common indication for revision, followed by aseptic loosening in four. In three hips (three patients) (0.5%), failure was possibly related to metal debris.

Considering that these patients are young and active these results are good, and support the use of resurfacing. Further study is needed to address the early failures, particularly those related to fracture and metal debris.

Patellofemoral joint degeneration is often considered a contraindication to medial unicompartmental knee replacement. We examined the validity of this preconception using information gathered prospectively on the intra-operative status of the patellofemoral joint in 824 knees in 793 consecutive patients who underwent Oxford unicondylar knee replacement for anteromedial osteoarthritis. All operations were performed between January 1998 and September 2005. A five-point grading system classified degeneration of the patellofemoral joint from none to full-thickness cartilage loss. A subclassification of the presence or absence of any full-thickness cartilage loss was subsequently performed to test selected hypotheses. Outcome was evaluated independently by physiotherapists using the Oxford and the American Knee Society Scores with a minimum follow-up of one year.

Full-thickness cartilage loss on the trochlear surface was observed in 100 of 785 knees (13%), on the medial facet of the patella in 69 of 782 knees (9%) and on the lateral facet in 29 of 784 knees (4%). Full-thickness cartilage loss at any location was seen in 128 knees (16%) and did not produce a significantly worse outcome than those with a normal or near-normal joint surface. The severity of the degeneration at any of the intra-articular locations also had no influence on outcome.

We concluded that, provided there is not bone loss and grooving of the lateral facet, damage to the articular cartilage of the patellofemoral joint to the extent of full-thickness cartilage loss is not a contraindication to the Oxford mobile-bearing unicompartmental knee replacement.

Anterior knee pain and/or radiological evidence of degeneration of the patellofemoral joint are considered to be contraindications to unicompartmental knee replacement. The aim of this study was to determine whether this is the case.

Between January 2000 and September 2003, in 100 knees (91 patients) in which Oxford unicompartmental knee replacements were undertaken for anteromedial osteoarthritis, pre-operative anterior knee pain and the radiological status of the patellofemoral joint were defined using the Altman and Ahlback systems. Outcome was evaluated at two years with the Oxford knee score and the American Knee Society score.

Pre-operatively 54 knees (54%) had anterior knee pain. The clinical outcome was independent of the presence or absence of pre-operative anterior knee pain. Degenerative changes of the patellofemoral joint were seen in 54 patients (54%) on the skyline radiographs, including ten knees (10%) with joint space obliteration. Patients with medial patellofemoral degeneration had a similar outcome to those without. For some outcome measures patients with lateral patellofemoral degeneration had a worse score than those without, but these patients still had a good outcome, with a mean Oxford knee score of 37.6 (SD 9.5). These results show that neither anterior knee pain nor radiologically-demonstrated medial patellofemoral joint degeneration should be considered a contraindication to Oxford unicompartmental knee replacement. With lateral patellofemoral degeneration the situation is less well defined and caution should be observed.

The Oxford hip and knee scores have been extensively used since they were first described in 1996 and 1998. During this time, they have been modified and used for many different purposes. This paper describes how they should be used and seeks to clarify areas of confusion.

The options for treatment of the young active patient with isolated symptomatic osteoarthritis of the medial compartment and pre-existing deficiency of the anterior cruciate ligament are limited. The potential longevity of the implant and levels of activity of the patient may preclude total knee replacement, and tibial osteotomy and unicompartmental knee arthroplasty are unreliable because of the ligamentous instability. Unicompartmental knee arthroplasties tend to fail because of wear or tibial loosening resulting from eccentric loading. Therefore, we combined reconstruction of the anterior cruciate ligament with unicompartmental arthroplasty of the knee in 15 patients (ACLR group), and matched them with 15 patients who had undergone Oxford unicompartmental knee arthroplasty with an intact anterior cruciate ligament (ACLI group). The clinical and radiological data at a minimum of 2.5 years were compared for both groups.

The groups were well matched for age, gender and length of follow-up and had no significant differences in their pre-operative scores. At the last follow-up, the mean outcome scores for both the ACLR and ACLI groups were high (Oxford knee scores of 46 (37 to 48) and 43 (38 to 46), respectively, objective Knee Society scores of 99 (95 to 100) and 94 (82 to 100), and functional Knee Society scores of 96 and 96 (both 85 to 100). One patient in the ACLR group needed revision to a total knee replacement because of infection. No patient in either group had radiological evidence of component loosening. The radiological study showed no difference in the pattern of tibial loading between the groups.

The short-term clinical results of combined anterior cruciate ligament reconstruction and unicompartmental knee arthroplasty are excellent. The previous shortcomings of unicompartmental knee arthroplasty in the presence of deficiency of the anterior cruciate ligament appear to have been addressed with the combined procedure. This operation seems to be a viable treatment option for young active patients with symptomatic arthritis of the medial compartment, in whom the anterior cruciate ligament has been ruptured.

We performed a clinical and radiological study to determine the rate of failure of the Charnley Elite-Plus femoral component. Our aim was to confirm or refute the predictions of a previous roentgen stereophotogrammetric analysis study in which 20% of the Charnley Elite-Plus stems had shown rapid posterior head migration. It was predicted that this device would have a high early rate of failure.

We examined 118 patients at a mean of nine years after hip replacement, including the 19 patients from the original roentgen stereophotogrammetric study. The number of revision procedures was recorded and clinical and radiological examinations were performed.

The rate of survival of the femoral stems at ten years was 83% when revision alone was considered to be a failure. It decreased to 59% when a radiologically loose stem was also considered to be a failure. All the patients previously shown in the roentgen stereophotogrammetric study to have high posterior head migration went on to failure. There was a highly significant difference (p = 0.002) in posterior head migration measured at two years after operation between failed and non-failed femoral stems, but there was no significant difference in subsidence between these two groups.

Our study has shown that the Charnley Elite-Plus femoral component has an unacceptably high rate of failure. It confirms that early evaluation of new components is important and that roentgen stereophotogrammetric is a good tool for this. Our findings have also shown that rapid posterior head migration is predictive of premature loosening and a better predictor than subsidence.

We inserted an electrode up the femoral neck into the femoral head of ten patients undergoing a metal-on-metal hip resurfacing arthroplasty through a posterior surgical approach and measured the oxygen concentration during the operation. In every patient the blood flow was compromised during surgery, but the extent varied. In three patients, the oxygen concentration was zero at the end of the procedure. The surgical approach caused a mean 60% drop (p < 0.005) in oxygen concentration while component insertion led to a further 20% drop (p < 0.04). The oxygen concentration did not improve significantly on wound closure. This study demonstrates that during hip resurfacing arthroplasty, patients experience some compromise to their femoral head blood supply and some have complete disruption.

Abnormal sagittal kinematics after total knee replacement (TKR) can adversely affect functional outcome. Two important determinants of knee kinematics are component geometry and the presence or absence of a posterior-stabilising mechanism (cam-post). We investigated the influence of these variables by comparing the kinematics of a TKR with a polyradial femur with a single radius design, both with and without a cam-post mechanism.

We assessed 55 patients, subdivided into four groups, who had undergone a TKR one year earlier by using an established fluoroscopy protocol in order to examine their kinematics in vivo. The kinematic profile was obtained by measuring the patellar tendon angle through the functional knee flexion range (0° to 90°) and the results compared with 14 normal knees. All designs of TKR had abnormal sagittal kinematics compared with the normal knee. There was a significant (p < 0.05) difference between those of the two TKRs near to full extension. The presence of the cam-post mechanism did not influence the kinematics for either TKR design. These differences suggest that surface geometry is a stronger determinant of kinematics than the presence or absence of a cam-post mechanism for these two designs. This may be because the cam-post mechanism is ineffective.

Polished, tapered stems are now widely used for cemented total hip replacement and many such designs have been introduced. However, a change in stem geometry may have a profound influence on stability. Stems with a wide, rectangular proximal section may be more stable than those which are narrower proximally. We examined the influence of proximal geometry on stability by comparing the two-year migration of the Exeter stem with a more recent design, the CPS-Plus, which has a wider shoulder and a more rectangular cross-section. The hypothesis was that these design features would increase rotational stability.

Both stems subsided approximately 1 mm relative to the femur during the first two years after implantation. The Exeter stem was found to rotate into valgus (mean 0.2°, sd 0.42°) and internally rotate (mean 1.28°, sd 0.99°). The CPS-Plus showed no significant valgus rotation (mean 0.2°, sd 0.42°) or internal rotation (mean −0.03°, sd 0.75°). A wider, more rectangular cross-section improves rotational stability and may have a better long-term outcome.

Introduction: A new procedure has been recently adopted to implant the Oxford medial unicompartmental arthroplasty (UCA). All cases are now implanted through a short incision without dislocation of the patella. The aims of this study were to assess the one-year results using this new technique and to determine if the outcome is dependent on surgical experience.

Method: The first 104 Oxford UCA’s (Phase 3) implanted by six surgeons under the care of two consultants were reviewed at one year. All operations were performed using the new technique. The average age at surgery was 68 years. All knees were scored pre-operatively and at review with the American Knee Society score. The cohort was divided into two groups; the first ten cases for each surgeon were included in a ‘learning’ group, whilst the remaining cases were included in an ‘experienced’ group.

Results: Overall the average ‘knee score’ improved from 37 points to 94 and the average ‘functional score’ from 50 points to 92. Average maximum flexion improved from 117° to 131°. The ‘knee score’ for the ‘learning’ group was 91 points. This was significantly less (p = 0.008) than the score of the ‘experienced’ group (96 points).

Conclusions: These results are significantly better than the best historical results of the Oxford (UCA), performed through an open approach with dislocation of the patella.

Despite impressive overall results at one year, lower knee scores were associated with a surgeons ‘learning curve’. After this ‘learning curve’, increased surgical experience led to further improvement with 90% achieving an excellent result, 8% a good, 2% a fair and 0% a poor result.

Introduction: In conjunction with a bilateral randomised control trial comparing the clinical outcome of two total knee arthroplasties (TKA), we carried out an in-vivo fluoroscopic analysis of both knees in the trial. Knee A, is a new mobile bearing posterior cruciate retaining TKA and Knee B, an established fixed bearing posterior cruciate retaining TKA.

Method: In an ethically approved study, video fluoroscopy was taken of both knees of seven patients performing three exercises; extension against gravity, flexion against gravity and a step up exercise. Ten images at ten-degree intervals over the flexion range were frame grabbed and digitised. The relationship of patella tendon angle (PTA) to knee flexion angle (KFA) was assessed using a newly developed computer system. Five normal knees in fit volunteers were also fluoroscoped and assessed.

Results: A similar pattern of results was obtai ed for all three exercises. Knee A behaved in a linear, more consistent fashion than Knee B, which behaved non-linearly. Analysis of variance showed this difference was significant for all three exercises (p < 0.039).

Conclusions: This bilateral study provides a powerful way of assessing the kinematics of two different knee implants. Knee A behaves in a linear predictable fashion that is nearer normal than Knee B. These results will be used in conjunction with a clinical outcome study and an RSA study to provide a complete assessment of a new TKA.

Introduction: The Oxford medial unicompartmental arthroplasty (UCA) is now routinely performed through a short incision without Dislocation of the patella. The aim of this study was to assess the one-year results of this new technique to determine whether it enhances the quality of outcome, as well as the speed of its achievement.

Method: The first 88 consecutive Oxford UCA’s (Phase 3) implanted into 75 patients by two consultant surgeons were scored pre-operatively and at review with the American Knee Society Score. The average age of the patients was 68.1 years; the male to female ratio was 0.9 to 1.

Results: At review, one patient (one knee) had died and one knee had been revised for infection. The other patients (86 knees) were examined at a mean of 1.3 years from surgery. The average ‘knee score’ improved from 37 points to 95 and the average ‘functional score’ from 51 points to 93. Average maximum flexion improved from 117° to 132°. The ‘knee score’ outcome categories at review were 87% excellent, 8% good, 2.5% fair and 2.5% poor.

Conclusions: Historical comparison of these results with the best results of the Oxford UCA, performed through an open approach with dislocation of the patella, suggest that the minimally invasive approach, in addition to faster recovery, improves the quality of outcome at one year.

A randomised controlled trial was performed to compare the clinical outcome for the two commonest types of anterior cruciate ligament (ACL) reconstruction. Methods: Patients undergoing elective anterior cruciate reconstruction were randomised into one of two groups. Group PT underwent reconstruction using a patella tendon autograft (n=14), whereas Group SG had a semitendinosus/gracilis autograft (n=18). The same surgeon performed all operations. IKDC self reported function and activity scores were recorded pre-operatively and at one and five years post operation. KT1000 values and muscle strength were recorded pre-operatively and one year post operation.

Results: No significant difference between groups was found for any measurement at one year despite adequate study power. At five year follow up patients in the PT group had superior scores in every category of the IKDC self reported function score (mean IKDC score for PT group = 83, mean IKDC score for SG = 75). The activities of squatting and kneeling revealed the greatest difference between groups. It was found that 71% of patients in the PT group achieved IKDC scores of 80 or over whereas only 61% of patients in the SG group achieved 1 KDC scores of 80 or over.

Conclusion: The study indicates that both techniques produce acceptable outcome for anterior cruciate ligament reconstruction but use of the patella tendon autograft may provide slightly more favourable results, especially for activities involving squatting and kneeling.

Aim: This study was designed to investigate the nature and extent of tibial translation (TT) during open kinetic chain (OKC) and closed kinetic chain (CKC) activity; recent reports have suggested that the anterior cruciate ligament (ACL) may be strained to an equal amount during CKC and OKC exercise.

Method: Fifteen unilaterally ACL deficient (ACLD) patients and six control subjects underwent fluoroscopic assessment while performing a passive extension exercise, an OKC resisted extension exercise, and a weight-bearing CKC exercise designed to reflect knee motion experienced during dynamic daily activity. Measurements of the patella tendon angle (the angle between the long axis of the tibia and the patella tendon) were obtained to calculate relative TT.

Results: The results show that in ACL intact (ACLI) knees the CKC exercise caused greater anterior TT than the OKC exercise from 0 to 60° of knee flexion (p< 0.05). No difference between ACLI and ACLD knees was detected during the CKC exercise. Maximum weight-bearing (CKC) TT was 8±3 mm. The ACLD tibia during the OKC exercise translated more than the ACLI tibia, and to the same extent as the CKC exercise at 10 to 200 of knee flexion. The ACLI tibia during OKC exercise translated to a maximum of 3±4 mm at 1 0° knee flexion.

Summary: This study has demonstrated that fluoroscopic analysis may be used to detect differences in the kinematics of ACLI and ACLD limbs during activity. It validates recent data demonstrating that the ACL may be strained during CKC exercise to an equal or greater amount than during OKC exercise, and shows that the ACLD knee kinematics are similar to the ACLI knee during CKC exercise. Factors other than the ACL may control the extent of maximal TT during weightbearing activity. This has important consequences for the development of rehabilitation regimes after ACL reconstruction. The commonly held assumption that CKC exercise will protect an ACL graft may not be valid.

A pilot study was performed to assess the feasibility of discharging patients undergoing unicompartmental knee replacement (UKR) within a day of surgery; both clinical and administrative issues were examined.

Logistics and responsibilities were organised prior to the study. Representatives of anaesthetics, pain team, orthopaedics, admissions, bed management, nursing, theatres, physiotherapy, radiology and outpatients were involved. Patients with medial compartment osteoarthritis undergoing unicompartmental knee replacement who passed strict exclusion criteria were recruited. Factors included; unsuitable home situation (no phone, excessive stairs, no support person), low tolerance to NSAIDS, and not living within a 25 mile radius of the hospital. To date seven NHS patients (mean age 60 years) have been recruited. All patients underwent preoperative assessment and counselling. The mean preoperative Oxford Knee Score was 24/48, the mean Knee Society Score (KSS) was 43/100 and average pain score was 14/50 indicating all patients had significant dysfunction and pain before operation. Average knee flexion was 111° and the average flexion deformity was 5°.

Each patient had a medial UKR using the minimally invasive approach and then underwent the accelerated recovery program. The program included pain control, accelerated rehabilitation, dedicated instructions and self assessment. Post operative pain was controlled by an intra-operative infiltration of local anaesthetic around the knee and large doses of NSAIDs. All patients were mobilised on the day of surgery and all except one who was delayed for administrative reasons) were discharged the following day. Patients were discharged in an extension splint and provided with post operative instructions including an emergency back up telephone number. A designated clinician made regular contact with the patient at home to assess progress. Patients were then assessed in clinic at 6 days, 13 days, and 6 weeks after surgery.

Patients average pain scores at 7 days and 14 days were 2/10 and 2.2/10 respectively. At 6 week follow up the average knee flexion was 124° and average flexion deformity was 1°. All patients were walking independently and painfree. No complications were encountered except one patient required further manipulation for limited knee flexion.

The new pain control protocol permits early mobilisation and discharge for patients undergoing UKR. Potential benefits include increased patient comfort, functional rehabilitation, avoidance of hospital induced infection and substantial cost benefits to the NHS. The pilot study demonstrates that, provided adequate communication is maintained between involved personnel, the program is both practical and safe. It now is planned to implement the accelerated recovery program for UKR as routine.

When the Oxford unicompartmental meniscal bearing arthroplasty is used in the lateral compartment of the knee, 10% of the bearings dislocate. A radiological review was carried out to establish if dislocation was related to surgical technique.

The postoperative radiographs of 46 lateral unicompartmental arthroplasties were analysed. Five variables which related to the position and alignment of the components were measured. Dislocations occurred in six knees.

Only one of the five variables, the proximal tibial varus angle, had a statistically significant relationship to dislocation. This variable quantifies the height of the lateral joint line. The mean proximal tibial varus angle for knees the bearings of which had dislocated was 9° and for those which had not it was 5°. In both groups it was greater than would be expected in the normal knee (3°).

Our study suggests that a high proximal tibial varus angle is associated with dislocation. The surgical technique should be modified to account for this, with care being taken to avoid damage to or over-distraction of the lateral soft tissues.

We have assessed the effectiveness of reconstruction of the anterior cruciate ligament (ACL) in reducing functional tibial translation (TT).

The gait of 11 ACL-deficient patients was studied using Vicon equipment before and after surgery. Measurements of the angle between the patellar tendon and the long axis of the tibia were obtained in order to calculate TT in the sagittal plane relative to the uninjured limb during standing and walking.

Before surgery, patients did not show abnormal TT on the injured side, but after surgery significant anterior TT was found in the operated limb for every parameter of gait.

Abnormal anterior TT occurring during activity does not seem to be reduced by reconstruction; rather, it increases. It may be that the increased translation results from relaxation of excess contraction of the hamstring muscles, since compensatory muscle activity no longer is required in a reconstructed knee. The reduction of TT may not be an appropriate objective in surgery on the ACL.